The input may be delivered through manipulations constrained to a surface, such as through the use of a so-called “touchscreen” interface. Touchscreens incorporate a contact sensing surface that overlays a visual display. Such an arrangement enables the user to deliver input by physical contact, e.g. by touching a fingertip to the touchscreen, moving that fingertip from place to place while in contact with the touchscreen, etc.
Various specific contacts or sets of contacts with a touchscreen may be assigned to correspond with specific functions for a device or system in communication with the touchscreen. For example, touching the screen with a fingertip, sliding the fingertip to the right while remaining in contact with the touchscreen, and lifting the fingertip away from the surface of the touchscreen may collectively be referred to as a “right swipe”, with a function such as “move screen contents to the right” being associated therewith.
However, a physical contact input and/or surface constrained input may not be desirable in all circumstances. For example, in at least certain instances there may exist concerns regarding contamination, potential damage to the touchscreen, difficulties in holding a physical screen while delivering inputs, etc. In addition, touchscreens typically are limited to receiving only input that may be delivered on a finite, two-dimensional surface.